J. j. thompson is credited with discovering the proton. electron. neutron. nucleus.

he discovered the electron

J.J. Thompson is credited with discovering the electron. Option B is correct.

Sir Joseph John Thomson was an English physicist and Nobel Laureate in Physics. In 1897, J.J. Thomson discovered the electron, (the first subatomic particle to be discovered), by experimenting with a Crookes, or cathode ray, tube. He proved that cathode rays were negatively charged. Moreover, he also studied positively charged particles in neon gas.  

Thomson was awarded the 1906 Nobel Prize in Physics.

operation overlord was the codename for the battle of normandy, the allied operation that launched the successful invasion of german-occupied western europe during world war ii. the operation was launched on 6 june 1944 with the normandy landings

your answer is

to dominate europe

and i know for a fact it can't be the others